Optical characteristics of a multilayer solar sail and their effect on its heliocentric motion

Abstract

The purpose of this work is to determine the influence of the optical characteristics of a thin multilayer solar sail on its orbital motion. First of all, the influence of the coefficients of reflection, scattering and absorption is investigated. These coefficients are computed on the basis of a mathematical model of the optical characteristics of a multilayer epitaxial thin film which is a solar sail itself. The paper considers the effect of temperature changes and sail surface degradation on its optical properties. Modeling of changes in optical characteristics is carried out drawing on an example of heliocentric flight from the Earth to Mercury applying locally optimal control laws. Applying the transfer matrix method and considering the distribution of solar spectral radiation optical parameters for two distinct constructions of a solar sail were obtained (aluminum and silver front coating).

Keywords

• solar sail
• non-ideal reflection
• optical characteristics degradation
• solar spectral radiation
• multilayer epitaxial films
• transfer matrix method
• flight from the earth to mercury
• locally optimal control laws